Date:         Thu, 18 Nov 1999 13:04:49 +0000
Reply-To:     roland.rashleigh-berry@virgin.net
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Roland <roland.rashleigh-berry@VIRGIN.NET>
Organization: N/A
Subject:      Re: Simple Date Problem
Content-Type: text/plain; charset=us-ascii

Minsup Song wrote:
>
> Dear
>
> Hello.  I have a simple(?) problem.  In the data set, there are date (year)
> variable. For example,
>
> OBS     Date
> 1          1970
> 2          1971
> 3          1973
> ...          ...
>
> I would like to extract some observation by Date.  For example, I would like
> to extract observation of which date is 1971.  But unfortunately, when I
> enter the command as below,
>
> Data temp;
>    Set Above;
>        If Date=1970;
> Run;
>
> Then, there is no observation.  I find out why.  The date is formatted by
> the date of 1960. 1.1.  For example, when I give the range like below,

It depends how you have stored this date. A date contains a day and
month as well as a year. Internally it is the number of days since
01jan60. Or have you stored just the year as an integer? If you have
then "if date=1970" should work. But if you have stored it as a normal
SAS date then you must use the test "if year(date)=1970".

> Proc Print Data=Temp;
>      Where 3000<=Date<=5000;
> Run;
>
> I can see observations of which date is about 1970s.  How can I treat this
> variable?  Can I use the Date variable more easily?

This is because 1970 is 10-11 years after 01jan60 and so the day range
is 3650-4014 days since a SAS date is the number of days since 01jan60.

Use the test "if year(date)=1970" and it will work.

> Thank you.

You're very Wellcome.   :o)

Roland